Apparatus for preventing accidental disconnection of pressure sources from well tools



H. J. URBANOSKY 3,411,810 APPARATUS FOR PREVENTING ACCIDENTALDISCONNECTION OF PRESSURE SOURCES FROM WELL TOOLS 2 Sheets-Sheet 1INVENTOR.

Alf/'01? y 7 v V //Z v V i Z x awn; sflz wwfiwwz w 6 Nov. 19, 1968 FiledOct. 14, 1966 Nov. 19, 1968 H. J. URBANOSKY 3,411,310

APPARATUS FOR PREVENTING ACCIDENTAL SCONNECTION OF PRESSURE SOURCES FROMWEL OOLS Filed Oct. 14, 1966 2 Sheets-Sheet 2 i l s Hera/0 J fl/a/raJAyINVENTOR.

United States Patent APPARATUS FOR PREVENTING ACCIDENTAL DISCONNECTIONOF PRESSURE SOURCES FROM WELL TOOLS Harold J. Urbanosky, Houston, Tex.,assignor to Schlumberger Technology Corporation, Houston, Tex., acorporation of Texas Filed Oct. 14, 1966, Ser. No. 586,806 8 Claims.(Cl. 28583) ABSTRACT OF THE DISCLOSURE A pressure-responsive latchingmeans for preventing premature disconnection of multi-sectional welltools containing high-pressure fluids. A piston or other member is urgedby fluid pressure within the well tool into latching engagment with stopmeans on the coupling means to prevent their premature disconnectionbefore the entrapped high-pressure fluid has been safely removed orvented.

This invention relates to well tools; and, more particularly, thisinvention pertains to new and improved pressure-responsive latchingmeans for preventing premature disconnection of multi-sectional welltools still containing high-pressure fluids.

The present trends toward smaller diameter Well bores as well as moreelaborate well-completion operations have made it necessary to make welltools substantially longer than heretofore. As a result, many well toolsare of such length today that they must be made in separable sections ofa convenient size that can be taken separately to the well and coupledthere before being used. Obviously, these sections must also bedisconnected before leaving the well.

It will be appreciated that coupling and uncoupling of suchmulti-sectional well tools must be done as quickly as possible tominimize the time that other well operations are halted. As a matter ofexpediency, therefore, a multi-sectional well tool will often beprogressively broken down as quickly as possible during the course ofits removal from the well bore to facilitate further handling of itsseveral sections. Ordinarily this procedure poses no particular problemand is quite acceptable.

Many well tools commonly in use today, however, sealingly enclosehigh-pressure fluids such as, for example, either fluid samples from thewell bore and earth formations or gases released by various combustiblessometimes used to actuate pistons or certain setting tools. It will beappreciated, therefore, that an accidental unconfined discharge of suchhigh-pressure fluids presents a definite hazard to equipment and nearbypersonnel. Although this hazard is recognized by all, in the haste ofquickly uncoupling a multi-sectional well tool to further speedoperations, it is not at all unlikely that it could be inadvertentlyuncoupled at a connecting joint where the high-pressure fluids wouldsuddenly escape and do considerable damage. Inasmuch as a well tool isgenerally coated with mud and the like as it is being retrieved from awell bore, it is, of course, impractical to rely only upon warninglabels or the like to prevent such accidents.

Accordingly, it is an object of the present invention to provide new andimproved means for preventing he inadvertent uncoupling of thoseconnections in multisectional well tools from which high-pressure fluidscould unexpectedly escape. This and other objects of the presentinvention are provided by arranging pressure-responsive latching means,such as a piston member in a bore, between a potential source ofhigh-pressure fluids and the section-coupling means. In this manner,should there still be high-pressure fluids confined in a portion of the"ice well tool about to be disconnected, the piston, or another memberaligned therewith, will be urged by the pressure differential intolatching engagement with stop means on the coupling means and preventtheir premature disconnection before the entrapped high-pressure fluidhas been safely removed or vented.

The novel features of the present invention are set forth withparticularity in the appended claims. The operation together withfurther objects and advantages thereof, may best be understood by way ofillustration and example of a certain embodiment when taken inconjuction with the accompanying drawings, in which:

FIG. 1 shows a multi-sectional well tool such as might employ thepresent invention;

FIG. 2 is a simplified, schematic representation of one section of theapparatus depicted in FIG. 1;

FIG. 3 is a cross-sectional elevational view of a'portion of theapparatus shown in FIG. 1 and depicting a preferred embodiment of thepressure-responsive latching means of the present invention; and

FIG. 4 is a cross-sectional view taken along the lines 4-4 in FIG. 3.

As will subsequently become apparent, it will be understood that thepresent invention has utility with any multisectional well tool havingthe capability of either accidentally or purposely entrapping a fluidunder high pressure. Accordingly, although the present invention isdescribed in conjuction with the particular multi-sectional tool 10shown in the drawings, this tool represents only a typical example ofhow the latching means of the present invention may be best employed. Itwill be understood, therefore, that the pressure-responsive latchingmeans of the present invention can be used to equal advantage with othermulti-sectional well tools of even a totally dissimilar nature. Inasmuchas the fluid-sampling tool 10 is fully described in copendingapplications Ser. No. 557,108, filed June 13, 1966, by Frank R. Whittenand Ser. No. 583,778, filed Oct. 3, 1966, by Harold J. Urbanosky, andthe details of its operation play no particular significance inunderstanding the present invention, only a brief description of theseand other details of this well tool is believed necessary to illustratethe usefulness of the present invention in a typical application.

Turning now to FIG. 1, the multi-sectional fluid-sampling apparatus 10is shown suspended from a multiconductor cable 11 in a borehole 12 andin position there adjacent to a formation interval 13 for collecting asample of producible fluids therefrom. The cable 11 is spooled in theusual manner from a winch (not shown) at the earths surface, with someof its conductors being arranged there for selective connection to apower source and typical indicating-and-recording apparatus. Thefluid-sampling apparatus 10 is comprised of a plurality of tandemlyarranged, self-contained testing tools 14 that are each capable ofindependent operation to take a fluid sample. As seen in FIG. 1, each ofthese tools 14 have extendible sample-admitting means 15 that arelongitudinally aligned along one side of the sample apparatus 10 andarranged for selective extension into sealing engagement with theexposed face of the earth formations such as at 13, for obtainingsamples of formation fluids.

As best seen in FIG. 12, in addition to the sample-admitting means 15,each testing tool 14 further includes sample-collecting means 16 forrecovering the fluid samples, and retracting means 17 for restoring thesampleadmitting means to their initial position. Thesepressureresponsive means 15-17 are independently controlled byselectively operable valves 1821 which, in response to electricalsignals from the surface, are opened in a particular sequence to admitborehole fluids to these pressureresponsive means as their source ofmotivating power.

Briefly, the sample-admitting means include an annular, elastomericsealing member 22 mounted on the outer end of a slidable tubular member23 that is fluidly sealed within the tool 114. A slidable tubular pistonmember 24 coaxially mounted around the smaller tubular member 23 willurge the sealing member 22 into sealing engagement with the earthformations whenever well control fluids are admitted through a branchedpassage 25 into an enclosed space 26 behind the piston by opening thevalve 20. The rear of the tool 14 will, of course, at that time beengaged against the opposite borehole wall. An enscapsulated shapedcharge 27 that is selectively detonatable from the surface is mounted inthe forward end of the tubular member 23 for use as required to provideincreased fluid communication with earth formations.

The sample-collecting means 16 includes fluid-receiving compartments 28and 29 separated from one another by a flow restrictor 30. A watercushion 31 is disposed in one compartment 28 and isolated therein afloating piston 32. Since the other compartment 29 is initially empty,formation fluids (at whatever the formation pressure is) will enter thecompartment 28 and move the piston 32 at a rate regulated by thedischarge of the water cushion 31 through the orifice and into the othercompartment.

To conduit a fluid sample from the sample-admitting means 15 to thereceiver, the sample-collecting means 16 also include fluid passagemeans, such as a series of interconnecting passages 33-35 between thesample-admitting means and the compartment 28. A normally-closed,piston-operated valve 36 is serially arranged with a normallyopen,piston-operated valve 37 to control fluid communication through thefluid passages 33-35. The so-called flow-line valve 36 prevents entry ofwell control fluids through the tubular member 23 and into thesamplereceiving compartment 28 as the apparatus 10 is being positioned,This flow-line valve 36 is controlled by selectively operable valve 19which, when opened, admits well control fluids through an associatedpassage 38 into an annular piston space 39. The so-called seal valve 37is arranged to close-off the sample compartment 28 once a fluid sampleis collected by opening the control valve 18 to admit well controlfluids through a passage 40 into an enclosed piston space 41.

In general, the retracting means 17 are comprised of one or more pistons42 arranged to develop a hydraulic pressure in a piston chamber 43 thatis greater than the hydrostatic pressure of the well control fluids. Anoutlet passage 44 from the chamber 43 is controlled by anormally-closed, piston-actuated valve 45 that is itself controlled bythe control valve 21. An extendible piston member 46 with an easilybroken, weakened forward end 47 is also provided to admit well controlfluids into the tool 14 should the hydraulic system fail.

In one manner of operating the tool 14, the apparatus 10 is positionedas shown in FIG. 1 opposite the formation 13. Then, the control valve 20is opened to simultaneously extend the piston 24 and the extendiblemember 46 on the opposite side of the testing tool 14 and parallel tothe piston 24. The flow-line valve 36 must, of course, be opened toadmit fluid samples into the sample-collecting compartment 28 once thesealing member 22 is sealingly engaged with one wall of the borehole.Should it be necessary, the shaped charge 27 is then detonated toprovide further fluid communication into the formation 13.

To retrieve the apparatus 10, the control valve 18 is first opened toclose the seal valve 37 and trap whatever fluids there may be in thesample-collecting compartment 28. The control valve 21 is then opened toin turn open the normally-closed hydraulic valve 45 and admit thehydraulic fluid into previously closed spaces 48 and 49 in front of thepiston member 24. Since the hydraulic pressure is greater than thehydrostatic pressure of the well control fluids in the piston space 26,as the hydraulic fluid enters these previously closed spaces 48 and 49,the piston 24 and the extendible member 46 will be returned to theirinitial positions. A piston-actuated equalizing valve 50 is so arrangedthat when the hydraulic valve 45 is opened, the equalizing valve will beopened by the hydraulic fluid to admit well control fluids into theextendible tubular member 23 to prevent the diiferential between thehydrostatic and formation pressures from holding the sealing member 22against the formation 13 when it is desired to retract it.

It will be appreciated, therefore, that whenever the apparatus 10 isretrieved from the well bore, each of the sample-receiving chambers 28in the tools 14 will sup posedly contain a high-pressure fluid whetherthis be a formation fluid sample or is merely the control fluid or mudin the well bore at the depth and pressure where the sample-admittingmeans .15 were employed. As previously mentioned, the pressure of theseentrapped fluids must be safely relieved to prevent their accidentaldischarge.

As best seen in FIG. 1, to keep the apparatus 10 within manageableproportions, it is preferred to combine two sample-admitting means 15 oftwo adjacent tools 14 and their associated valves into a single integralbody, as at 51, and to enclose their respectively associatedsamplecollecting means 16 in separate housings, as at 52 and 53, thatare tandemly connected at the opposite ends of the integral body.Appropriately arranged interconnectors and (such as more fully describedin the aforementioned copending Urbanosky application) are respectivelyused to couple the adjacent free ends of the housings 52 and 53 to stillothers of the tools 14 and to couple these housings to the opposite endsof the body 51.

Accordingly, the upper end of one of the intermconnectors 55 is shown inFIG. 3, as it will appear as it is being coupled to the adjacent lowerend of its associated sample-admitting section 51. The lower end of theinterconnector 55 has already been connected to the housing 52 asexplained in greater detail in the aforementioned copending Urbanoskyapplication. To accommodate various electrical conductors 56 running tothe other tools therebelow, a tubular conduit 57 is extended through thefluid compartments 28 and 29 along the central axis of thesample-collecting section 52 and fluidly sealed, as by O-rings 58, ateach end. The floating isolating piston 32 (not seen in FIG. 3) must, ofcourse, be made annular and is fluidly sealed around the tubular conduit57 by 0- rings (not shown).

A fluid connection must also be provided between the sample-admittingsection 51 and the sample-collecting section 52 that corresponds to thepassage 35 (FIG. 2) beyond the seal valve 37. Therefore, as seen in FIG.3, to make this fluid connection, a longitudinally projecting tubularmember 59 is secured to the sample-admitting section 51 and adapted forreception in a complementary longitudinal bore 60 in the upper end ofthe interconnector 55. O-rings 61 around the free end of the tubularextension 59 complete the fluid-tight connection.

To mechanically couple the interconncetor 55 to the sample-admittingsection 51, the lower end of the sampleadmitting section iscounterbored, as at 62, and adapted to receive the adjacentreduced-diameter end 63 of the interconnector. Selectively operableconnecting means 64 are provided such as an externally threaded ring orcollar 65 that is loosely mounted around the reduced end 63 of theinterconnector 55 and adapted for threaded engagement with internalthreads 66 within the counterbore 62 in the sample-admitting section 51.A shoulder 67 on the interconnector 55 and a split-ring 68 respectivelyimmediately below and above the loose collar 65 confine the collaragainst significant longitudinal movement.

Once the tubular extension 59 is oriented with its associated bore 60,the sections 51 and 52 (with the interconnector 55 already thereon) arebrought together so the collar 65 can be threadedly engaged with thethreads 66 and tightened upon further rotation of the collar. As

the collar 65 is tightened, the sections 51 and 52 will be pulled stillcloser together and the tubular extension 59 will be inserted into itsrespective bore 60. The sections 51 and 52 and interconnector 55, ofcourse, do not rotate as the collar 65 is being rotated. An O-ring 69around the extremity of the end portion 63 fluidly seals thesampleadmitting section 51 relative to the interconnector 55 wheneverthe two members are finally coupled.

Once the tubular member 59 is partially in its receptive bore 60,electrical interconnection between the two sections 51 and 52 isaccomplished by opposed, axially aligned, multi-contact mating connectormembers 70' and 71 respectively mounted in the adjacent ends of thesection 51 and interconnector 55. As fully explained in theaforementioned Urbanosky application, one of the connector members 70 iscapable of limited rotation and longitudinal movement and the otherconnector member 71 is secured against both rotational and longitudinalmovement. In this manner, as the two adjacent ends of the section 51 andinterconnector 55 are brought together into the position shown in FIG. 3by the threaded collar 65, the movable connector 70- is appropriatelyoriented relative to the fixed connector 71 by means of a cooperativelyarranged key 72 and longitudinal slot 73 in tubular members 74 and 75supporting the connectors so as to permit their accurateinterconnection.

It will be appreciated, of course, that whatever fluids are entrapped inthe sample-collecting section 52 will usually be at a substantialpressure. After the apparatus has been returned to the surface, theentrapped fluids are supposedly removed through appropriately arrangedports (not shown) in each sample-collecting section, as at 52, by meansof suitable high-pressure manifolds and containers (not shown). Asalready discussed, however, it is quite possible that the connection as,for example, at 64 between the sections 51 and 52 could be inadvertentlydisconnected before the high-pressure fluids have been removed.

Accordingly, as seen in FIGS. 3 and '4, in accordance with the presentinvention, premature disconnection of the sections 51 and 52 isprevented by providing pressureresponsive latching means, such as alateral bore 76 located to at least partially intersect the bore 60 anda piston 77 slidably disposed and fluidly sealed therein, that areadapted for latching cooperation with the connecting means 64. Toaccomplish this cooperation, the outer opening of the lateral-bore 76 islocated immediately below at least a portion of the internalcircumferential surface 78 of the collar 65. This internal surface 78 ofthe collar 65 is appropriately recessed, as at 79, to provide aninclined surface portion 80 (FIG. 4) that is gradually tapered outwardlyand in the direction of rotation for threading the collar onto thethreads 66 and then intersected by stop means, such as a substantiallyradial surface portion 81 in the recess.

Thus, should there still be pressure in the sample chamber 28 and bore60, the outer end 82 of the piston 77 will be urged outwardly againstthe internal circumferential surface 78 of the threaded collar 65. Itwill be appreciated, therefore, that rotation of the collar 65 throughno more than one full turn in the direction to unthread it will bringthe recess 79 over the extended piston end 82. Then, since the pressuredifferential will force the outer end 82 of the piston 77 furtheroutwardly and into the recess 79, continued rotation of the collar 65 inthat direction will be positively halted whenever the outer piston endmoves into latching engagement with the radial end surface 81 of therecess. Once, however, all pressure has been relieved from thecompartment 28, the collar 65 can, of course, be retightenedsufficiently for the camming action of the inclined surface 80 of therecess 79 against the outer piston end 82 to restore the piston 77 toits retracted position. The collar 65 can then be returned in theopposite direction to continue disconnecting it from the threads 66. Itwill be realized,

of course, that a separate member (not shown) could be slidably disposedin the bore 76 and so arranged that its outer end is instead urged intothe recess 79 by the piston 77.

It will be appreciated, therefore, that the cooperative latching actionof the piston 77 with the surfaces 80 and 81 in the recess 79 in thecollar will prevent the premature disconnection of a fluid-containingwell tool whenever this fluid is at a pressure greater than thatexterior of the tool. Moreover, it should also be repeated that althoughthe present invention has been described as having particular utilitywith sample-collecting tools, other typical Well tools such as settingtools, tight-hole testers, and the like, will be equally improved by thepresent invention. In this manner, pressure-responsive latching meansarranged in accordance with the principles of the present invention willenable multi-sectional well tools to be disconnected without fear thatone section will be disconnected at a point whereby high-pressure fluidscould suddently escape unchecked and without warning.

While a particular embodiment of the present invention has been shownand described, it is apparent that changes and modifications may be madewithout departing from this invention in its broader aspects; and,therefore, the aim in the appended claims is to cover all such changesand modifications as fall within the true spirit and scope of thisinvention.

What is claimed is:

1. In a Well tool having first and second separable bodies with adjacentends adapted for interconnection with one another, first fluid-passagemeans extending from Within said first body to its said adjacent end,second fluidpassage means extending from within said second body to itssaid adjacent end, and a chamber adapted to contain a high-pressurefluid in said tool and connected to one of said fluid-passage means, theimprovement comprising: first means for releasably interconnecting andsealing said fluid-passage means including a tubular member connected tosaid first fluid-passage means and projecting from said first body end,a complementary bore in said second body end connected to said secondfluid-passage means and adapted to receive said tubular member and firstsealing means adapted for sealing said tubular member in said bore;second means for releasably interconnecting and sealing said adjacentbody ends including a threaded ring rotatably mounted around one of saidbody ends and adapted for threaded engagement with the other of saidbody ends, and second sealing means adapted for sealing said body endsto one another; and means responsive to a pressure differential betweensaid fluid chamber and the exterior of said tool for preventingdisconnection of said interconnecting means including a second borecommunicating one of said fluid-passage means with the exterior of saidtool, piston means sealingly received in said second bore and movabletherein by such a pressure differential, and latching means responsiveto movement of said piston means for preventing rotation of saidthreaded ring from threaded engagement with said other body end.

2. The well tool of claim 1 wherein said latching means include stopmeans on said threaded ring and means movable by said piston means intolatching engagement with said stop means,

3. The well tool of claim 1 further including camming means on saidthreaded ring for disengaging said latching means upon rotation of saidthreaded ring into further threaded engagement with said other body endwhenever there is no pressure differential between said fluid chamberand said tool exterior.

4. The well tool of claim 3 wherein said latching means include saidstop means on said threaded ring and means movable by said piston meansinto latching engagement with said stop means.

5. The well tool of claim 1 wherein said second bore is in said one bodyend and is terminated in an opening adjacent to said threaded ring; saidpiston means include a rigid member with an outer end movable from aposition within said second bo-re to a position partially extending fromits said opening; and said latching means include stop means on saidthreaded ring adapted to engage said outer end of said rigid memberwhenever said outer end of said rigid member is partially extended fromsaid bore opening and prevent its further rotation of said ring fromthreaded engagement with said other body end.

6. The Well tool of claim 5 wherein said stop means include a recess insaid threaded ring adapted to receive said outer end of said rigidmember and having an end surface adapted for engagement with saidpartially-extended outer end of said rigid member whenever said threadedring is rotated from threaded engagement with said other body end.

7. The well tool of claim 6 further including a surface in said recessinclined outwardly and in the direction of rotation for unthreading saidthreaded ring whereby rotation of said threaded ring into furtherthreaded engagement with said other body end will cam said outer end ofsaid rigid member back into said second bore whenever there is nopressure differential between said fluid chamber and said tool exterior.

8. In a well tool having first and second separable bodies with adjacentends, a pressure chamber in one of said bodies, and passage meansextending from said pressure chamber through said body ends to the otherof said bodies, the improvement comprising: means for releasablyinterconnecting said adjacent body ends including a threaded ringrotatably mounted around one of said body ends and adapted for threadedengagement with the other of said body ends, and stop means on saidthreaded ring; means movable into latching engagement with said stopmeans in response to a pressure differential between said pressurechamber and the exterior of said tool for preventing unthreading of saidthreaded ring upon rotation of said threaded ring away from threadedengagement with References Cited UNITED STATES PATENTS 1,652,542 12/1927Perry 28592 X 1,706,051 3/ 1929 Auchincloss. 2,245,847 6/1941 Bagby28583 2,591,531 4/1952 Fishback. 2,743,781 5/1956 Lane 285306 X3,041,090 6/1962 Ashe et al. 3,092,404 6/1963 MacWilliam 285-334.43,345,084 10/1967 Hanes et al 28527 FORETGN PATENTS 781,227 2/ 1935France. 863,470 1/ 1941 France.

EDWARD C. ALLEN, Primary Examiner.

THOMAS F. CALLAGHAN, Assistant Examiner.

